This application concerns novel flame retardant organic phosphorus-phosphorus oxyacid compounds and compositions. These compounds contain two or more phosphorus atoms in each molecule. The flame retardant compounds of this invention may be utilized as flame retardants by incorporating these compounds within or coating a more flammable organic material. In particular, it relates to flame retardant compounds and a flame retardant organic resin compositions, which are free from toxicity problems due to the absence of halogen gas generated during combustion or molding as in the use of a halogen-containing flame retardant compound.
Basic nitrogen containing salts of organic polyphosphorus compounds were produced by Blount in U.S. Pat. No. 6,054,515 and utilized in flame retardant compositions. The organic phosphorus-phosphorus oxyacids compounds of this invention are novel. These novel compounds are an improvement over the basic salts of organic polyphosphorus compounds because they are a much better flame retardant compounds and cost less to produce. When the organic phosphorus-phosphorus oxyacid compound is incorporated in or on a flammable organic material it produces an intumescent composition. When this intumescent composition is exposed to a flame for a few seconds it begins to char and form bubbles within the char thereby protects the substrate against heat and fire damage for an appreciable time. This intumescence also reduces the amount of smoke produced. The organic phosphorus-inorganic phosphorus oxyacid compounds promote initial intumescence at a low temperature, which is much lower that required when a basic nitrogen salt of organic polyphosphorus compound or an organic phosphorus compound is utilized as the flame retardant compound. The flame retardant compounds of this invention will also with stand a higher temperature than the organic phosphorus compounds and basic nitrogen containing salts of organic polyphosphorus compounds before decomposing, and allows them to be mixed in thermoplastic resin to produce flame retardant reins.
The object of this invention is to produce organic phosphorus-inorganic phosphorus oxyacid compounds, it""s salts and compositions containing these compounds which are capable of rendering organic material less flammable. These flame retardant compounds may be used in the production of insulation foam, flexible foams, building components, coating agents, surfactants, molded plastic products and many other uses.
In one respect, the invention comprises reacting phosphorus halogen compounds, containing phosphorus atom with a valence of 3-4, with an inorganic phosphorus oxyacid compounds with phosphorus atoms with a valence of 5 and an organic compound to produce organic phosphorus-inorganic phosphorus oxyacid compounds. Another aspect, the invention comprises utilizing the organic phosphorus-phosphorus oxyacid of this invention by incorporating in, or apply on a more flammable organic material to render the organic material less flammable. Another aspect of the invention is a process to prepare the organic phosphorus-phosphorus oxyacid compound comprising contacting and reacting:
A) a phosphorus halide compound containing a phosphorus atom with a valence of 3-4;
B) an inorganic phosphorus oxyacid compound containing a phosphorus atom with a valence of 5;
C) an organic compounds that will react with a phosphorus halide or a phosphorus oxyacid; under conditions sufficient to prepare the organic phosphorus-inorganic phosphorus oxyacid compound.
Organic phosphorus-phosphorus oxyacid compounds has the general formula of:
(R)w(P)x(PO4)yHz
Wherein x is a number 1-4, y is a number 1-3, z is a number 3 to 9 and w is a number 1-3 and selected from the compounds containing a radical selected from the group consisting of:
xe2x80x94SH, xe2x80x94CH2Cl, xe2x80x94CH2Br, CH2I, xe2x80x94CN, xe2x80x94NO, xe2x80x94COCl, xe2x80x94COBr, xe2x80x94SO2Cl, xe2x80x94SO2Br, xe2x80x94COOH, xe2x80x94S2OH, COOxe2x80x94, 
xe2x80x94NH2, Znxe2x80x94, xe2x80x94MgCl, xe2x95x90Hg, xe2x80x94OH, and xe2x80x94Nxe2x80x94Pxe2x95x90.
Another aspect of this invention is to produce a flame retardant composition which comprising mixing and reacting:
A) a phosphorus halide compound containing a phosphorus atom having a valence of 3-4;
B) an inorganic phosphorus oxyacid compound containing a phosphorus atom with a valence of 5;
C) an organic compounds that will react with a phosphorus halide and/or a phosphorus oxyacid; then add and mix or react
D) carbonization auxiliaries;
then add and mix
E) carbonization accelerating compounds;
F) heat reflecting substance;
G) filler;
xe2x80x83under conditions sufficient to prepare the organic phosphorus-inorganic phosphorus oxyacid compound.
In another aspect, according to this invention there is provided a flame retardant basic salt of organic phosphorus-phosphorus oxyacid compound and composition produced by a process comprising of mixing and reacting:
A) phosphorus halide compound containing a phosphorus atom having a valence of 3-4;
B) inorganic phosphorus compound containing a phosphorus atom having a valence of 5;
C) organic compound that will react with a phosphorus halide or a phosphorus oxyacid; then add, mix and react;
H) basic inorganic or organic salt forming compound, thereby producing a basic salt of organic phosphorus-phosphorus oxyacid;
then add and mix
D) carbonization auxiliaries;
E) carbonization accelerating compounds;
F) heat reflecting compound;
G) filler;
xe2x80x83under conditions sufficient to prepare the salt of organic phosphorus-phosphorus oxyacid.
In another aspect, according to this invention, there is provided a flame retardant thermoplastic resin composition which comprises (1) thermoplastic resin, (2) organic phosphorus-phosphorus oxyacid or it""s salt, (3) carbonization auxiliaries, (4) metal containing compound having a carbonization accelerating effect, (4) comb-like polymer and (5) filler.
The components may be utilized in any suitable amount but preferably:
1. An phosphorus halogen compound, which contains a phosphorus atom containing a valence of 3 or 4, in the amount of 25 to 100 parts by weight;
2. Inorganic phosphorus oxyacid compound, which contains a phosphorus atom with a valence of 5, in the amount of 10 to 100 parts by weight;
3. Organic compound that will react with a phosphorus halide and/or phosphorus oxyacid, in the amount of 10 to 100 parts by weight;
4. An amount of 5% to 30% by weight of the flame retardant compound or composition is added to or on the flammable organic material;
5. Basic salt forming compound in the amount of 0 to 100 parts by weight;
6. metal containing compound having a carbonization accelerating effect in the amount of 0 to 30 parts by weight;
7. Comb-like polymer, in the amount of 0 to 30 parts by weight
8. Heat reflecting compound, in the amount of 0 to 30 parts by weight.
9. Carbonization auxiliaries, in the amount of 0 to 100 parts by weight.
10. Filler, in the amount of 0-200 parts by weight.
Any suitable phosphorus halide compound, that contains a phosphorus atom with a valence of 3-4, may be used in this invention, such as, but not limited to, phosphorus trihalides such as phosphorus trichloride, phosphorus tribromide, phosphorus triflouide, phosphorus triiodide, and phosphorus with a valence of 5 such as phosphorus pentachloride, phosphorus pentabromide, phosphorus pentaflouride, and phosphorus oxyhalides, such as phosphorus oxytrihalides such as phosphorus oxytrichloride, phosphorus oxytribromide and phosphorus oxytriflouride. Phosphorus trichloride is the preferred phosphorus halide compounds.
Any suitable inorganic phosphorus oxyacid compound which contains a phosphorus atom with a valence of 5 may be used in this invention. Suitable inorganic phosphorus compounds include, but not limited to, phosphoric acid, polyphosphoric acid, pyrophosphoric acid, phosphorus oxide, salts of hydrogen phosphoric acid, phosphonic acid, ammonium hydrogen phosphate, ammonium polyphosphate, triphosphorus acid, phosphinic oxide, phosphorus esters, phosphorus trioxide, phosphorus pentioxide, metaphosphoric acid, phosphorus acid, hypophosphorus acid, and mixtures thereof. Phosphoric acid is the preferred inorganic phosphorus oxyacid.
Any suitable organic compound that will react with a phosphorus halide and or a phosphorus oxyacid may be utilized in this invention. Suitable organic compounds maybe substituted, saturated or unsaturated or mixtures thereof. Suitable organic compounds are organic compounds with one or more active hydrogen and/or halide and/or metal radicals. These compounds may be aliphatic, aromatic, aliphatic-aromatic, heterocyclic and mixtures thereof. Suitable organic compounds include, but not limited to, alcohols, polyalcohols, alkylalcoholamines, epoxides, polyepoxides, epichlorohydrin, chlorohydrin, organic halide may also be used such as alkyl halide, carboxylic acids and anhydrides, polycaboxyl acids and anhydrides, isocyanates, polyisocyanates, thioalcohols, thiophenols, phenoplasts, aldehydes, halogenated alcohols and polyalcohols, halogenated organic acids and polycarboxyl acids, sulphonic acid chlorides, organic esters, organic ethers, thioethers, halomethyl compounds, ketones, nitriles, sulphonic acids, amines,polyamines, polyesteramide, amino compounds, aminoplasts, alkyl magnesium chloride, alkenes, alkynes, alkyl halide, organometallic compounds such as methyl magnesium chloride, dialkyl mercury, dialkyl zinc, dialkyl magnesium, alkali metal carboxylic acids and polycarboxylic acids, alkyloxy alkali metals, alkali metal cyanides, alkaline earth metal cyanides, calcium carbide, arylalkenes, organic polyenes, aminophenols, proteins, terpenes, oils, fats, amides, polyamides, imides, polyimides, organic phosphates, organic phosphates, organic phosphonates, organic phosphines and other organic phosphorus containing compounds, carbohydrates, lignins, cellulose, amino acids, arylalkynes, halogenated alkenes, aminoalcohols, organic carbonates, etc. and mixtures thereof.
Any suitable organic compound containing the following radicals and mixtures thereof may be utilized in this invention:
xe2x80x94SH, xe2x80x94CH2Cl, xe2x80x94CH2Br, CH2I, xe2x80x94CN, xe2x80x94NO, xe2x80x94COCl, xe2x80x94COBr, xe2x80x94SO2Cl, xe2x80x94SO2Br, xe2x80x94COOH, 
xe2x80x94NH2, Znxe2x80x94, xe2x80x94MgCl, xe2x95x90Hg, xe2x80x94OH, and xe2x80x94Nxe2x80x94Pxe2x95x90.
An suitable salt forming compound that will react with an organic phosphorus compound or inorganic phosphorus compound may be used in this invention. Suitable salt forming compounds include, but not limited to, compounds containing alkali metals, alkaline earth metals, metals, and nitrogen containing compounds such as compounds containing ammonium radicals, ammonia, amines, amino compounds, urea condensates, biuret, cyanuric acid, cyamelide, partially hydrolyzed urea condensates, polyamines, and aminoplasts, other nitrogen containing compounds and mixtures thereof. Nitrogen containing salt forming compounds such as alkylanolamine compounds are the preferred salt forming compounds, particularly ethanolamine. The basic salt forming compounds may be utilized in the amount of 0 to 100 parts by weight. It is not always necessary to use basic salt forming compounds but when used it is utilized in the amount of 5-100 parts by weight.
Any suitable carbonization auxiliaries may be utilized in this invention. Suitable carbonization auxiliaries are compounds that in the presence of fire assist the formation of a carbonization foam or char, such as, additives that produce acidic components in the pyrolysis mixture, such as phosphorus acids, boric acids or sulfuric acids. These acidic components are compounds such, for example, acids or salts, or their derivatives of sulfur, boron and phosphorus, such as, boron-phosphates, phosphates, and polyphosphates of ammonia, amines, polyamines, amino compounds, thioureas and alkyanolamines, but boric acid and its salts and their derivatives, organic phosphorus compounds and their salts, halogenated organic phosphorus compounds, their salts and their derivatives may also be used for this purpose.
Phosphorus containing compounds, such as, boron-phosphates, phosphates, and polyphosphates of ammonia, amines, polyamines, amino compounds, thioureas and alkyanolamines, boric acid and its salts and their derivatives, organic phosphorus compounds and their salts, halogenated organic phosphorus compounds, their salts and their derivatives may also be used for this purpose. The carbonization auxiliaries and other flame retardant agents may be used in quantities of 0 to 100 parts by weight. In many compositions they are not necessary but when used, it is used in the amount of 5 to 100 parts by weight.
The nitrogen containing salts of phosphorus acids are the preferred carbonization compounds, such as amine phosphates, amine salts of organic phosphorus compounds, amino phosphate, amino salts of organic phosphorus compounds and amino condensation salt of inorganic and organic phosphorus compounds. The amino condensation salt of phosphorus compounds are produced by contacting the amino condensation compounds with phosphorus containing compound that will react with an amino compound, under conditions sufficient to prepare an amino condensation salt of a phosphorus containing compound. Suitable inorganic phosphorus compounds include, but not limited to phosphoric acid, pyrophosphoric acid, triphosphoric acid, metaphosphoric acid, phosphorous acid, hypophosphorous acid, phosphinic acid, phosphinous acid, phosphine oxide, phosphorus trihalides, phosphorus oxyhalides, phosphorus oxide, mono-metal hydrogen phosphates, ammonia dihydrogen phosphate, bromated phosphates, alkaline metal dihydrogen phosphate and halogenated phosphate-phosphite and their halides and acids. Organic phosphorus compounds include, but not limited to, alkyl, cyclic, sty] and alkyl-aryl phosphorus compounds, such as, alkylchlorophosphines, alkyl phosphines, alkyl phosphates, dialkyl hydrogen phosphates, dialkyl alkyl phosphonates, trialkyl phosphates, organic acid phosphates, organic phosphonate esters, aryl phosphates, aryl hydrogen phosphates, halogenated phosphonates esters and mixtures thereof, Amino condensation borates may be produced by contacting boric acid and amino condensation compound under conditions sufficient to prepare the amino condensation berates which may also be utilized and also ammonia borates may be used. Amino condensation boron-phosphates may be produced by contacting boron-phosphates and amino condensation compounds under conditions sufficient to prepare amino condensation boron-phosphate compounds which may also be utilized. The salt forming phosphorus containing compounds will react with the amino condensation compounds to form an amino condensation salt of a phosphorus containing compound which may also be used. The carbonization auxiliaries are utilized in the amount of 0 to 100 parts by weight. It is not always necessary to utilize carbonization auxiliaries but when they are used they are utilized in the amount of 5 to 100 parts by weight.
Any suitable filler may be used in this invention. The fillers that may be utilized in the flame retardant mixture are usually insoluble in the reaction mixtures. They may be inorganic substances, such as, alkali metal silicates, alkaline earth metal silicates, metal silicates, glass beads or hollow beads. Hydrated aluminum oxide is the preferred inorganic compound. They may be organic substances such as urea, melamine, dicyandiamide, and other cyanuric derivatives or their formaldehyde resins, aminophosphates, amino salts or organic phosphates, phenol-aldehyde resin powder, powdered coke, graphite, graphite compounds, lignins, cellulose and mixtures thereof The organic halide flame retardant compounds may also be added as fillers. Fillers may be used in the amount of 0 to 200 parts by weight. Fillers are not always necessary but when used are used in the amount of 5 to 200 parts by weight.
Any suitable organic material which is more flammable than the organic phosphorus-phosphorus oxyacids or salt of organic phosphorus-phosphorus oxyacid compounds of this invention may be used in this invention, Any suitable plastic resin composition or mixtures thereof and any suitable natural organic material may be used in this invention and mixtures thereof. These materials may be in the form of a solid, cellular, suspension, emulsion or solution. Suitable plastic resin include, but not limited to, vinyl dienes, vinyl diene copolymers, polyesters, polyester resins, phenoplasts, aminoplasts, polyepoxy resins, polyurethanes, furans, polyamides, polyimides, polycabonates, silicones, polyethers, thioplasts, polytetrafluoroethlylene, polysulfones, urethane-epoxy resins, urethane silicate resins or foams, cellulose nitrates, regenerated cellulose, cellulose esters, cellulose ethers, cyanoethyl cellulose, lignin-phenol-formaldehyde, lignin-amino-formaldehyde and mixtures thereof.
Suitable natural products include, but not limited to, wood, cellulose, lignin-cellulose, lignins, paper, cotton, wool, linen, dammars, copols, other natural resins, natural rubber, natural proteins, e.g., soya bean protein, silk glues gelatin, etc., modified cellulose and mixtures thereof.
Any suitable isocyanate may be used in this invention, organic polyisocyanates are preferred. The commercially available ones are preferred such as tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, polymethylene polyphenyl isocyanate, diphenymethane-4,4xe2x80x2-diisocyanate, 3-methlydiphenyl-methane-4,4xe2x80x2-diisocyanate, m- and p-phenylenediisocyanante, polyphenylmethylene isocyanates obtained by phosgenation, commercially known as xe2x80x9ccrude MDIxe2x80x9d, modified polyisacyanates and mixtures thereof. Suitable organic polyisocyanate are exemplified by the organic diisocyanates which are compounds of the general formula:
Oxe2x95x90Cxe2x95x90Nxe2x80x94Rxe2x80x94Nxe2x95x90Cxe2x95x90O
wherein R is a divalent organic radical such as an alkylene, aralkylene or arylene radicals, such radicals may contain 2 to 20 carbon atoms. Any suitable compound with active hydrogens may be reacted with the polyisocyanates to produce polyurethane products, The preferred compound with active hydrogens are polyols. Polyurethane, catalyst, blowing agents, surfactants, foam stabilizers and fillers may also be used. Any suitable polyepoxy compounds may be used in this invention such as allyl glycidyl ether, tert-butyl glycidyl ether and other polyepoxides.
Any suitable thermoplastic resin may be used in this invention. Suitable thermoplastic resins include the olefin polymers. The olefin polymers include, for example, homopolymers and copolymers of olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, octene-1 and the like, and specific samples thereof include polyethylene, polypropylene, ethylene-polypropylene copolymers, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymers, and ethylene-octene-1 copolymers.
Said olefin polymers also include copolymers of said olefin with polar monomers comprising the olefin unit as the main constituent, specifically ethylene-vinyl acetate copolymer, ethylene-methylmethacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl alcohol copolymer and the like. These olefin polymers may be used alone or in combination of two or more. The thermoplastic resin in this invention includes homopolymers and copolymers of unsaturated carboxylic acids and their alkyl esters such as acrylic acid, methacrylic acid, methylacrylate, methylmethacrylate, and the like and vinyl esters of saturated carboxylic acids such as vinyl acetate, vinyl butrate and the like. These homopolymers and copolymers may be used alone or in combination of two or more.
Said vinyl aromatic polymers include, for example, homopolymer and coploymers of styrene monomers such as styrene, a-methylstyrene and vinyl styrene, and specific examples thereof polystyrene, poly-a-methylstyrenes, polyvinyltoluene, styrene-a-methylstyrene copolymers and the like. The vinyl aromatic polymers further include, for example, copolymers of styrene with acrylonitrile monomer, maleimide monomer, acrylic acid ester monomer, maleic acid monomer, and specific examples thereof include styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, styrene-methylacrylate copolymer, styrene-maleic anhydride copolymer and the like. Said vinyl aromatic polymers may also be modified with a rubbery polymer, and the rubbery polymer includes, for example, polybutadiene, styrene-butadiene copolymer, butadiene-acrylonitrile copolymer, ethylene-propylene-diene copolymer, butadiene-acrylic acid ester copolymer and the like. These vinyl aromatic polymers may be used alone or in combination of two or more.
Furthermore, the thermoplastic resin in this invention includes also engineering plastics such as polyphenylene ether, rubber-modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyamide, polycarbonate, polyacetal, polysulfone, polyethersulfone, polyphenyene sulfide, polyarylate, polyamide-imide, polyetheramide, polyetherketone, polyetheretherketone, polyimide and the like. The thermoplastic resins in this invention may also be chemically modified products, blends and alloyed products of the above-mentioned thermoplastic resins or may be reinforced with glass fiber or the like.
As the thermoplastic resin to be used in this invention, among the above-mentioned examples, particularly preferable in industry are those consisting of one or more olefin polymers mentioned above or those consisting of one or more vinyl aromatic polymers in view of the moldability and mechanical properties of a flame retardant resin composition prepared by mixing the thermoplastic resin with an organic phosphorus-inorganic phosphorus oxyacid compound or composition, composition and/or a salt of an organic phosphorus-phosphorus oxyacid compound, a comb-like polymer, a metal-containing compound having a carbonization accelerating effect, component, a carbonization auxiliary, and a filler.
When halogen-containing resins, for example, polyvinyl chloride, polyvinyldiene chloride, chlorinated polyethylene, chlorosulfonated polyethylene and the like, are used as polymer of this invention, the flame retardant can be improved, but the halogen-containing resins become a source of generating a toxic gas due to the halogen element contained therein when the resins are burned, and hence, are not the optimum resins to be used in this invention. The thermoplastic resins may be utilized in the amount of 100-200 parts by weight.
Component (2), a organic phosphorus-phosphorus oxyacid compounds which are produced by reaction component A, a phosphorus halogen compound containing phosphorus which has a valence of 3, and component B, an inorganic phosphorus oxyacid compound containing phosphorus which has a valence of 5 and an organic compound that will react with a phosphorus halide and/or a phosphorus oxyacid compound. The organic phosphorus-phosphorus oxyacid compounds maybe utilized in the amount of 5 to 50 parts by weight.
Component (3), salt of organic phosphorus-phosphorus oxyacid compounds are produced by the process of this invention as stated above, by reacting component A, a phosphorus halide compound, component B, an inorganic phosphorus oxyacid compound and an component C, an organic compound, thereby producing an organic phosphorus-inorganic phosphorus oxyacid compound which is then reacted with component C, a salt forming compound. The preferred salt of an organic phosphorus-phosphorus oxyacid compounds to be use to flame retard thermoplastic resins are nitrogen containing salts of organic phosphorus-inorganic phosphorus oxyacid compounds. The preferred nitrogen containing compound are amino compounds such as urea, urea condensates, melamine or a combination of melamine and another amino compound and/or ammonia compound. The preferred organic phosphorus compounds are organic phosphonate compounds, for example, dimethyl methyl phosphonate. The salts of organic phosphorus-phosphorus oxyacids may be utilized in the amount of 5 to 50 parts by weight.
A comb like polymer consisting of a polyethyene main chain and a polyoxyalkylene main chain and a polyoxyalkylene side chain can be obtained by, for example, graft-copolymerization of a cyclic ether such as ethylene oxide or propylene oxide unto a saponification product of an ethylene-vinyl acetate copolymer, esterification between ethylene-vinyl acid copolymer and polyethylene glycol, poly-propylene glycol or the like, copolymerization of ethylene with w-hydroxypoylethylene oxide macromonomer, or the like. The production process of a comb like polymer comprising heating an ethylene-vinyl acetate copolymer and an alcohol in the presence of an alkali catalyst to saponify them, removing the alcohol and then introducing alkylene oxide there into to form a graft copolymer.
A metal-containing compound having carbonization accelerating effect used in this invention increases the amount of carbonization residue after combustion, thereby enhancing the flame retarding effect. These compounds include, but not limited to, alkaline earth metal borates such as magnesium borate, calcium magnesium borate and the like, manganese borate, zinc borate, metal oxides of titanium oxide, tin oxide, nickel oxide, zinc oxide and the like, ferrocene, dimethylglyoxime copper, acetyl-acetonatocopper, hydroxyquinoline nickel and the like, zinc thiocarbamate compounds such as zinc dimethylthio-carbamate, zinc di-n-butyldithiocarbamate and the like, mercaptobenzothiazole zinc compounds such as mercaptobenzothiazole zinc and the like, salicyladehyde zinc compounds such as salicylaldehyde zinc compounds such as salicylaldehyde zinc and the like, metal hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium magnesium hydroxide, zirconium hydroxide and the like.
The most preferable compounds are selected from zinc oxide, the zinc thiocarbamate compounds, the mercaptobenzothiazole zinc compounds, the salicyaldehyde zinc compounds, zinc borate and the alkaline earth metal borates.
The components are mixed and reacted under conditions sufficient to prepare the organic phosphorus-phosphorus oxyacid compounds and/or composition and flame retarded organic materials. Many of the reactions will take place at ambient temperature and pressure. Most of the reactions are exothermic and may require cooling. Chlorine and HCl is given off in the reaction. Some of the reactions may be speeded up by using an elevated temperature of 100xc2x0 to 300xc2x0 C. and increased pressure. When a gas is used it may be necessary to use increased pressure to compress the gas in order to form a liquid.
It is preferred for the phosphorus halide compound to contain a phosphorus atom which has a valence of 3-4 so that the phosphorus atom will have 1 or 2 remaining valences to react with the inorganic phosphorus oxyacid compound which contain a phosphorus atom which has a valence of 5. The inorganic phosphorus oxyacid had active hydrogens to react with the 1 to 4 free valences of the organic phosphorus compound produced by the reaction of the phosphorus halide with the organic compound. The organic phosphorus compounds with a coordination number of four (xe2x80x9cpentavalentxe2x80x9d phosphorus compounds) will also react with inorganic phosphorus oxyacid compounds. The organic phosphates has an active oxygen on the phosphorus atom which will react with the inorganic phosphorus oxyacid compounds. The organic phosphorus-phosphorus oxyacid compounds may be produced as a neutral, mildly acidic or moderate acidic compounds.
The salt of organic phosphorus-phosphorus oxyacid compounds are usually produced by mixing and reacting the phosphorus halide with a phosphorus oxyacid and an organic compound to produce an organic phosphorus-phosphorus oxyacid compound and then the salt forming compound is added and reacted thereby producing a salt of organic phosphorus-phosphorus oxyacid compound. These reactions are usually exothermic, but in some reactions it is necessary to heat the mixture up to 300xc2x0 C. Then the comb-like polymer, carbonization auxiliaries, carbonization accelerating compound and fillers are added and mixed with the salt of organic phosphorus-phosphorus oxyacid compound to form a flame retardant composition. The flame retardant salt of organic phosphorus-phosphorus oxyacid compound and/or the flame retardant composition is added on or mixed in the more flammable organic material.
In this invention, the method of mixing the thermoplastic resin, the organic phosphorus-phosphorus oxyacid compound, salt of organic phosphorus-phosphorus oxyacid compound and/or composition, comb-like polymer consisting of a polyethylene main chain and a polyoxyalkylene side chain and a metal-containing compound having a carbonization accelerating effect is not critical. All the above components, thermoplastic resin, organic phosphorus-phosphorus oxyacid compound and/or composition and/or salt of organic inorganic phosphorus-phosphorus oxyacid and/or composition, comb-like polymer, carbonization auxiliaries and metal containing compound may be added simultaneously then mixed together by any suitable means. They may be mixed together by using a Banbury mixer, an open roller, a kneader, a single or multiple screw extruder or the like with or without or after mixing by a Henschel mixer, a tumbler mixer or the like. The said mixture is heated until the thermoplastic resin softens or melts then is thoroughly mixed then extruded or molded into a desired shape. The organic phosphorus-phosphorus oxyacid compound and basic salt forming compound may be added separate with the thermoplastic resin, and are reacted when the mixture is heated.
The flame retardant thermoplastic composition of this invention may if necessary, have added thereto a heat stabilizer, an antioxidant, a light stabilizer, a lubricant, an antifogging agent, a pigment, a blowing agent, a fluorescent agent, a release agent, a processing aid, a reinforcing agent, and the like which are generally added to a thermoplastic resin, depending upon the uses of the composition. A known flame-retardant such as a halogen-containing flame retardant, an inorganic flame retardant or the like may also be added to the thermoplastic resin.
The following examples which describe certain preferred embodiment of the processes may, of course, be varied as described above with similar results. This invention is not limited to the examples below. Parts and percentages are by weight unless otherwise indicated.
The following Reference Examples shows method for producing the organic phosphorus-phosphorus oxyacid compounds and composition, basic salt of organic phosphorus-phosphorus oxyacid compounds and compositions, and the comb-like polymer consisting of a polyethylene main chain and a polyoxyalkylene side chain.